BY MARYE ANNE FOX
Department of Chemistry
University of Texas, Austin
The prediction of ab initio calculations that a C 18 cyclocarbon would possess alternating single and triple bonds seems to be verified in a recent study, which reports the laser flash pyrolysis of a well-characterized precursor to the title compound. Structural evidence for its formation via a retro-Diels-Alder reaction of an appropriate  annulene is presented.
F. Diederich, Y Rubin, C.B. Knobler, R.L. Whetten, et al., "All-carbon molecules: evidence for the generation of cyclo[l 8]carbon from a stable organic precursor," Science, 245, 1088-90, 8 September 1989. (University of California, Los Angeles)
A novel intermediary state of matter, a helical smectic A* mesophase, has been discovered during the search for new ferroelectric liquid crystals. This layered phase shows a high degree of chirality and possesses relatively large molecular fluctuations. Since it is miscible with a classical smectic...